Interactions Between Ticks and Lyme Disease Spirochetes

Abstract

Borrelia burgdorferi sensu lato causes Lyme borreliosis in a variety of animals and humans. These atypical bacterial pathogens are maintained in a complex enzootic life cycle that primarily involves a vertebrate host and Ixodes spp. ticks. In the Northeastern United States, I. scapularis is the main vector, while wild rodents serve as the mammalian reservoir host. As B. burgdorferi is transmitted only by I. scapularis and closely related ticks, the spirochete-tick interactions are thought to be highly specific. Various borrelial and arthropod proteins that directly or indirectly contribute to the natural cycle of B. burgdorferi infection have been identified. Discrete molecular interactions between spirochetes and tick components also have been discovered, which often play critical roles in pathogen persistence and transmission by the arthropod vector. This review will focus on the past discoveries and future challenges that are relevant to our understanding of the molecular interactions between B. burgdorferi and Ixodes ticks. This information will not only impact scientific advancements in the research of ticktransmitted infections but will also contribute to the development of novel preventive measures that interfere with the B. burgdorferi life cycle. caister.com/cimb 113 Curr. Issues Mol. Biol. Vol. 42 Curr. Issues Mol. Biol. 42: 113-144. caister.com/cimb Interactions Between Ticks and Spirochetes Pal et al.scapularis are highly specific. Limited studies have shed light on these complex pathogen-tick interactions (Munderloh and Kurtti, 1995;Fikrig and Narasimhan, 2006); a recent review summarizes our most current state of knowledge about the interactions between B. burgdorferi and I. scapularis ticks (Kurokawa et al., 2020). Vector competence, which depends on genetic determinants influencing the vector's ability to transmit a pathogen, also shapes interactions involving the tick, pathogen, and host (de la Fuente et al., 2017). With the advent of genetic tools for creating Borrelia mutants (Samuels et al., 2018) (see also Radolf and Samuels, 2021) and the current availability of the I. scapularis genome (Gulia-Nuss et al., 2016;Miller et al., 2018), investigators will have increasingly robust tools for studying Borrelia-tick interactions, both during the arthropod phase of the spirochete life cycle and at the interface with the mammalian host. A few borrelial proteins already have been demonstrated as prerequisites for spirochete-vector interactions, particularly with receptors in select tick organs, such as the gut or salivary gland (

Occurrence of juvenile Dermacentor reticulatus ticks in three regions in Poland: the final evidence of the conquest

“…Influence of co-feeding of D. reticulatus and I. ricinus on Borrelia burgdorferi -infected rodents cannot be simply predicted, as ticks from genus Dermacentor were not experimentally confirmed as vectors of any B. burgdorferi (s.l.) spirochaetes [ 39 , 40 ]. It would be interesting to investigate whether the prevalence of Borrelia burgdorferi (s.l.)…”

Identification of microRNAs in the Lyme disease vector Ixodes scapularis

“…There is now a good understanding of tick immune pathways and their interactions with B. burgdorferi [19][20][21], but it is still uncertain how B. burgdorferi avoids clearance. B. burgdorferi must traverse tick salivary glands during transmission [71]. Since saliva/salivary gland proteins can enhance B. burgdorferi transmission into the vertebrate host, characterization of molecular interactions at the tick bite site and the tick salivary glands is expected to facilitate vaccine development [22,23], since promoting immunity against tick salivary proteins could neutralize tick bites and pathogen transmission.…”

“…While it is known that other tick-borne pathogens such as Anaplasma marginale must replicate inside salivary glands for efficient transmission [76], the details of B. burgdorferi replication are less well understood. Indeed, borrelial spirochetes invade the tick salivary gland via an unknown mechanism [71] and might be carried to the host dermis via tick saliva. Several salivary gland genes are upregulated in B. burgdorferi -infected Ixodes scapularis nymphs compared with uninfected ones [24], suggesting a significant role for salivary gland gene regulation in B. burgdorferi infection and transmission.…”

Protozoan and Microbial Pathogens of House Cats in the Province of Tekirdag in Western Turkey

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